Concrete stair



Patented Mar. 14, 1939 UNITED STATES BIATENT GFFCE 5 Claims.

This invention relates to iireproof stairways of which the component parts consist of a concrete aggregate reinforced with concealed reinforcing and which are formed, braced, and poured at the job site. The object of this improvement is to eliminate the labor required to lay-out the stair proper and to simplify the framing of the formwork necessary in constructing stairways of this character. Other objects of this improvement include uniform risers and treads, a uniform thickness of the supporting stair slab, armored protection at the risers and exposed corners of the stair somt, and other features hereinafter described and claimed. This invention consists of a shop fabricated skeleton framework of a non-structural value, constructed of light gauge metals shaped to eliminate all lay-out work ordinarily required to establish the risers, treads, and thickness of the supporting stair slab and which serves as a pattern to guide the framing of the formwork at the sides and soflit of the proposed stairway. The formwork carries and supports the concrete aggregate and metal framework described hereinafter, and the exposed p-arts of the metal framework provide armored protection at parts most apt to be damaged in stairways of this type. The elimination of the lay-out work and simplifying of the formwork expedite construction and represents substantial savings over other types of stairways using structural shapes that form, carry, and support concrete fillers.

One form of the improvement is illustrated in the accompanying drawing in which Figure No. 1 indicates a vertical side elevation sho-wing a fragment of a concrete stairway to establish the position of the metal framework in relation to a completed stairway, Figure No. 2 is a front elevation showing a fragment of the. framework, the View shown indicating a half elevation which is symmetrical about center line, Figure No. 3 is a section through the framework taken at points A-A. The invention is clearly illustrated in the drawing in which the metal riser forms I, supporting arms 2, framing bars 3, and the anchors 4, all connected together, form the metal skeleton framework which I claim, and the purpose of this framework is to serve as a pattern outlining in profile the desired stairway and to establish the riser lines 6, tread lines 8, stair pitch line I, top 9 and bottom I0 lines of the supporting slab. The width of the stair (lines E I-I I), and the point 5 where the riser line 6 bisects the tread line 8.

The metal riser forms I are constructed of steel sheets stiffened by bending the upper portion of theV sheets to form a nosing that will provideadditional tread space and fabricated with holes at both ends at the location indicated for rapid Vfastening to the supporting' arm 2, and are provided with metal anchors I securely fastened to the riser forms I and spaced to prevent the riser I from pulling away from the concrete. The supporting arms 2 are securely fastened to the framing bars 3 and are shaped and bent inwardly so as to be concealed in the concrete. The metal framing bars 3 are provided with holes for the purpose of nailing or bolting the skeleton framework to the forms` to prevent movement during the pouring of the concrete. This improvement dispenses with all labor and materials ordinarily required to lay-out, form and finish each riser and enables the finisher to proceed with the troweling of the treads immediately. It is. to be noted that the framework provides an even and flat surface at the sides and soiiit of the stairway simplifying the formwork and the feature of this invention is that its usefulness continues'` throughout the building of the stairway and in addition provides armored protection at the corners of the completed stair most apt to be damaged.

In erecting concrete stairways of this character, different methods would be followed depending on job conditions, a suggested method however Would be to first assemble the metal skeleton framework on a flat surface such as a floor, and then apply the formwork to encase the sides of the framework, the second step is to set the unit in its proper position and complete the formwork at the stair soflit, after the entire unit has been braced proceed to pour the concrete aggregate. More or less Variation of the exact details of constructing is possible Without departing from the spirit of this invention; I desire therefore not to limit myself to the exact form of the construction sho-wn and described but intend in the following claims, to point out all of the invention disclosed herein.

I claim as new, and desire to secure by Letters Patent:

1. In a reproof stairway using temporary forms that shape and support a reinforced concrete aggregate, the combination of a metallic skeleton framework providing armored protection at each riser, the framework consisting of side framing bars with angle bracket riser suprports fastened to said framing bars, bent plate riser forms with connections provided at each end securing riser to said supporting arms and strap anchors fastened to the riser forms at the rear.

2. In. a reproof stairway using temporary forms that shape and support a reinforced concrefte aggregate, the combination of a metallic skeleton framework providing armored protection at the edges of the soffit, the framework consisting of side framing bars with angle bracket riser supports fastened to said framing bars, bent plate riser forms with connections provided at each end securing riser to said supporting arms and strap anchors fastened to the riser formsV at the rear. Y

3. In a rep-roof stairway using temporary forms that shape and support a reinforced concrete aggregate, the combination of a skeleton framework that simplifies the framing of the formwork by establishing construction lines, the skeleton framework being of metallic shapes consisting o-f siderframing bars with angle bracket riser supports fastened to said framing bars, bent plate riser forms with co-nnections provided at each end securing riser to said supporting arms, and strap anchors fastened to the riser forms at the rear.

4. In a fireproof stairway using temporary forms that shape and support a reinforced concrete aggregate, the combination vof metallic skeleton framework providing permanent metal forms at each riser, the framework consisting Yof side framing bars with angle bracket riser supports fastened to said framing bars., bent plate riser forms with connections provided at each end securing riser to said supporting arms,

Y and strap anchors fastened to the riser forms at -the rear.

5. In Va reproof stairway using temporary forms that shape and support a reinforced concrete aggregate, the combination of a metallic skeleton framework consisting of side framing bars with angle bracket riser supports fastened to said framing bars, bent plate riser forms with connections provided at each end securing riser to said supporting arms, strap anchors fastened to the riser forms at the rear, and which provides armored protection at theY riser and stair sofit, that simplies the framing of the formwork, that 4establishes construction lines and that provides a permanent form at each riser.

WALTER JAMES MCAVER. 

